materialize-form | material_select is not a function - materialize

Question

I am using materialize-sass and simple_form gems along with materialize-form gem on a brand new app. I add materialize-sass gem and all seems to work fine. Once i add the materialize-form gem following the gem githib page and reload the app, i start getting the following error.
Uncaught TypeError: $(...).material_select is not a function
at Object.initSelect (materialize-form.self-89fda0734fca24f0d2616fd681f296b51ac68a36ebdc1fcec6767a6543545064.js?body=1:9)
at Object.init (materialize-form.self-89fda0734fca24f0d2616fd681f296b51ac68a36ebdc1fcec6767a6543545064.js?body=1:3)
at HTMLDocument.<anonymous> (materialize-form.self-89fda0734fca24f0d2616fd681f296b51ac68a36ebdc1fcec6767a6543545064.js?body=1:23)
at fire (jquery.self-bd7ddd393353a8d2480a622e80342adf488fb6006d667e8b42e4c0073393abee.js?body=1:3233)
at Object.fireWith [as resolveWith] (jquery.self-bd7ddd393353a8d2480a622e80342adf488fb6006d667e8b42e4c0073393abee.js?body=1:3363)
at Function.ready (jquery.self-bd7ddd393353a8d2480a622e80342adf488fb6006d667e8b42e4c0073393abee.js?body=1:3583)
at HTMLDocument.completed (jquery.self-bd7ddd393353a8d2480a622e80342adf488fb6006d667e8b42e4c0073393abee.js?body=1:3618)
I have ensured that jquery is loaded before materialize and also materialize is loaded before materialize-form.
my application.js looks like:
//= require jquery
//= require materialize-sprockets
//= require rails-ujs
//= require turbolinks
//= require materialize-form
//= require_tree .
$(document).on('nested:fieldAdded', function(event) {
window.materializeForm.init()
})
still i get the error.

Answer 1

I complete understand your problem. But I can give you some great advice in order you don't have these kind of issues.
1.- Create a materialize.js page under the Javascript folder
2.- This is a small example how I manage my inits: (The use of turbolinks is optional)
$(document).on('turbolinks:load', function() {
$('.modal').modal({});
$('.tabs').tabs();
$('.collapsible').collapsible();
$(".dropdown-trigger").dropdown();
$('.materialboxed').materialbox();
$('select').formSelect();
});
3.- This is how I manage my requires in the application.js file:
//= require jquery
//= require rails-ujs
//= require jquery2
//= require materialize
//= require materialize-sprockets
//= require turbolinks
//= require_tree .
4.- My gems in order materialize works:
gem 'materialize-sass', '~> 1.0.0'
gem 'jquery-rails', '4.1.1'
And thats literally it, I hope this works for you!